Ferrari 275 GTB/C by CMC or Corvette C2 by Exoto

Both nice but I’d go with the CMC Ferrari 275 GTB/C.

Ferrari 4 me too ! 

Steve

Actually, the comparison isn't on equal footing.  The Exoto is from their extremely low-end "Motorbox" series.  It's akin to a Hollywood "A" lister movie star doing a role in a "B" movie.  They do it for the money.  Motorbox is literally in the Maisto category of detail and quality.  Fortunately, CMC doesn't have an equivalent "low-end" offering in its lineup, as does Exoto.  Consequently, it's a "no contest" as the CMC wins easily.  

I have to disagree that Exoto Motor Box is on the level of Maisto. The 1967 Corvette C2 has some extremely nice detail work by Exoto on it, the side pipes are very well done with actual cutout slots on the heat shields and the exhaust pipe exit is one of the best I have seen on any diecast with side pipes. The seats in the Corvette are not a hard plastic either, you can feel them give like an actual seat with springs and cushion. The Maisto Premiere Edition while nicer than the rest of their line up falls short of the detail in the Exoto Motor Box line. Another example are the rims on the Exoto Motor Box are very nicely detailed while the rims on my Maisto Premiere Edition Mustang GT don't come close to the Exoto Motor Box when viewed in person. 

Here are some photos of the Exoto Motor Box 1967 Corvette C2 small block 327. Of the four Maisto diecast I have one of them the premiere edition none of them come close to the Exoto Motor Box Corvettes I have. The 1967 Corvette C2 427 big block Green Exoto Motor Box has the same nice detail as this Yellow one. 

Here are some photos of the Maisto Premiere Edition Mustang GT.

I'd say you're both kind of right.  The Motorbox line is better than anything Maisto has ever done, but it is nowhere near the level of anything CMC has ever done.